Optical training apparatus



June 21, 194-9. R Q DEHMEL OPTICAL TRAINING APPARATUS 2 Shee ts-Sheet 1 Filed April 17, 1945 C. DEHMEL INVENTOR.

1AFTDF Y June 21, 1949. R. c. DEHMEL 2,474,096

OPTICAL TRAINING APPARATUS Filed April 1?, Q1945 2 Sheets-Sheet 2 Ac SouRce.

A'RTIFlClAL HoRtzoN INVENTOR. RICHARD c DEHMEL ATTCIR EY Patented June 21, 1949 UNITED STATES PATENT OFFICE orricar. TRAINING APPARATUS Richard 0. Dehmel, Summit, N. J.

Application April1'7, 1945, Serial No. 588,788

4 Claims. 1

My invention relates to apparatus for the ground training of aircraft pilots, and particularly ground trainers of the type in which the optical effect of actual flight is produced on the pilot usin the device.

An object of this invention is to provide an improved ground training apparatus constructed and arranged to simulate the optical effect of actual flight on a student pilot as it would appear to him during actual flight maneuvers.

A further object is to provide an improved apparatus in a ground trainer adapted, during simulated maneuvers such as dives, rolls, and level flying, to picture to the ilot the relative position of the aircraft and earth as it would appear under corresponding conditions of actual flight.

The invention will be more fully set forth in the following description referring to the accompanying drawings, and the features of novelty which characterize my invention will be pointed out with particularity in the claim annexed to and forming a part of this specification.

Referring to the drawings,

Fig. 1 is a perspective View, partly exposed, of a ground training apparatus constructed in accordance with an embodiment of the present invention; and

'Fig. 2 is a diagrammatic view illustrating the preferred arrangement of the operating parts employed in the training apparatus shown in Fig. 1.

In accordance with my invention a landscape or terrestial image is projected on a screen, such as the windshield of a trainer and in accordance with the manipulation of coordinatable simulated aircraft controls this image is caused to rise, fall, rotate, bank or turn in precisely the same manner as the earth would appear to be moving to an occupant of an actual aircraft piloted through I similar maneuvers. The coordinatable simulated controls, such as the stick, rudder, throttle, etc., are disposed in the trainer cockpit and need not be illustrated since a detailed description is unnecessary for a complete understanding of the present invention. For example, these controls and the associated control equipment may be of the type disclosed in my Patent 2,365,693, granted January 2, 1945, for Aircraft training apparatus, wherein there is shown means for energizing a steering motor in response to manipulation of the controls for turning or banking, and for operating simulated flying instruments, such as a bank indicator, artificial horizon, etc.,

2 in response to corresponding manipulation of the controls.

There is shown in Fig. 1 an aircraft trainer comprising optical apparatus generally indicated at I and a grounded cockpit or cabin 2 for the student pilot. The optical apparatus includes a movable transparent film or diapositive 3 shown for the purposes of illustration as in the form of a terrestial globe presenting a panorama 4. A light source 5 and a projection mechanism 6 are employed for projecting on a translucent screen, such, for example, as the windshield I of the trainer a portion of the panorama 4.

Preferably, the element constituting the diapositive 3 is substantially in the shape of a sphere so that it can present a continuous panorama and is arranged to be rotated about two separate axes perpendicular to each other. To this end the spherical element 3, which has an opening 8 at its lower side is mounted on a suitable stationary support or pedestal 9. This support provides trunnion bearing [0 and II for a generally horizontally disposed shaft l2 that carries a mounting l3 for a servo-motor or the like [4. This motor is connected to the spherical element at its top by means of a spider structure I6 and is positioned so that its operating shaft I5 is normally in -a generally vertical position, i. e. perpendicular to the plane of the mounting l3. The shaft [2 is operatively connected through a coupling ll to a second servo-motor l8. Accordingly, operation of the motor i4 is effective to rotate the diapositive in azimuth to represent turn, and operation of the motor i8 is effective to pitch the diapositive in a vertical direction.

The light source 5 is disposed adjacent to and at the inner side of the diapositive and is attached to a bracket 59 secured to the support 9 and comprises a high-powered lamp 20, Fig. 2, of suitable candle power, a reflector 2| and light focusing lenses 2? and 23. The purpose of the illuminating unit is to light brilliantly a portion of the diapositive for projecting an image, such as indicated by the arrow, on the objective lens 24 of the projection apparatus 6 that is disposed at the outer side of the diapositive opposite to the light source 5.

The projection apparatus 6 is mounted on a fixed pedestal 25, Fig. 1, and comprises a cylindrical housing within which projecting means such as a pair of Dove prisms 26 and 21 are positioned. The function of the projection unit 6 is to scan the spherical surface at 3 and cast an image on the windshield 'i of the trainer cabin 2,

3 or other screen. The windshield 'l is preferably composed of a translucent material so that any image formed by the projection unit 6 can be seen by an observer or student operating the controls inside the trainer 2. It should be understood that the screen need not be translucent and that the image can be projected from the rear of the student on to a screen in front of him. The operation of the projection unit 6 is similar to that of :the optical projector: disclosed r inulmy 310 co-pending application Sr'N. 498Z906,-filed 'August 14, 1943, for Aircraft navigating and training apparatus."

The Dove prisms are employedetolrotateethee image represented by the arrow at the diaposi- 15 tive in accordance with simu1ated-' rotati-on"-or roll of the aircraft, and thereby cause thetprojected image to rotate on the screen II To this end, the prisms which are suitably alignedealongr their projection axes aregarranged to be rotated 20 by a servo--motor-i'28 that? issoperated" in :accorde ance with the simulated roll of the trainer.-

The shaft 290i the motor is connected through gearing 30,: Fig; 2,. toea countershaft 3| having;

securedxthereto driving1;gears':32.-;and 33 whichc25,

operate the ringsgears 35wandu35 secured :to the. prisms v- 26' and 21 ires-pectively. The ringgears surrounding the prisms-are Yprovided with ofi -set collars (not shown) forming in effect stub shafts for the annular supporting bearings 36 and 31. 30;

The prisms 26 and 'Z'Iirotate: in like directions-,-, but theprism 26 .rotates-:at-one-half of the speed. of prism 27. This-correction-iactor is due $0 the fact that in this '-type .prism the projected: image is rotated at twicethespeedofthe prism itself;

Itwill now be apparent :thatif thGBSUI'ffiCGlOfA the transparent'spherewat 3is-coated1with a black; and -white,: or color: image of any landscapebr; terrestial scene rwhichu-mayg include the horizon; skyjand earth, an imagezmay be cast on-the windn shield brother screen'and: caused to ;move in such 2 manner as to depicts the combinedLeiifectsof turning, climbing, ,divingior rolling of an aircraft." The image is causedztorotate\inisazimuthby-thei servo-motor: l4;'1Fig.-ii 2; which:.:is: :shown: for, ex-.

ampleii as a Selsyn unit energized from the correspending .idliVlll'gl-funifil 383 The unit; 38 sis :posi tioned .in accordancemrith:operationi of the steering motorL'SM throughssuitable reduction-geareing 39 :and: operatingzjshaftiilfls The steeringimoe ton can. be suitably*energizediinrresponse' topper ation :ot the coordinatableecontrolsim the=manri-;- ner .=ab.ove referred tozand: described in my: afore. said patent.

The: efiecti of; pitch :is obtained by energizing."

the servo-motor. ornrselsynirunits I8 by: a: .corresponding' driving: unit-r4 I that Tisv :suitably, posie A tioned in response"torotationr2of :the;pitch ele ment 420i the artificial horizondevice 43 respon-ia 60 be. understood however rthatimy invention: is not 7 0.

limited to thisspecificittypeio .iartificialohorizorri device and that: any. suitablee-apparatuse having; elements: responsive to changes: in pitch; and? change inithe position-01)zbankiorzroll cambeused; inpracticing. my inventiomxm The efiects of roll are obtained by energizing the servo-motor or Selsyn unit 28 in accordance with the position of the artificial horizon element 45 that is responsive to the condition of bank or roll. The rotatable element 45 positions the corresponding Selsyn unit 46 in accordance with the degree of bank, and as in the case of the pitch element, the driving current is suitably amplified at 41 for properly energizing the unit 28. The torque amplifiers at 44 and 4'l' may'tbet ofs'any well known type and detaileddescription thereof is unnecessary for the purposes of this invention.

It is to be understood that the azimuthal and pitchwrotationeof the spherical diapositive need not be produced by Selsyn units, but may be CausedbIVFfiTlYCOHVEHiEIl-t means, such as belt and pulley, apparatus, ,or a servo mechanism. Also, itis not necessary'that the motion which introduces the roll efiect be obtained by the prisms of the projection device 6. This motion may alternativelyabe provided-by means cream-additional gimbal rin'g at. ith'e suspensiomof; the: spherical'i element which", may. be -tiltedaccording; to: the! angle of 2roll'.f,. that. event, aesimpleprojection-i lens system is employed at 24.to.,form animage=r of a portion of. azscenicleffectsuchs as -;indicated' byithe arrow.

The pictureionthesurfaceofsthe spherical-unite may be formed: by coating such ,surfaces with at. photographic emulsion .iand iexposingethei-sphere progressively through'i aisl'it; lens". toef orma,- continuance image, such as ,seenuby anobservor view..-- ingthe sky 'andl'groun'dfin allifdirections. around; him."

In electrical trainers. where the azimuth an l the" pitch, and; the ro'lllfangle. dcanotiappear ase. shaft'movements", but inst'eadas electrical poten-e tials, the shafts Land. l5 suppflntingvthe diapositive unit maybe rotatedjby electricservofol-low.

- iup, units; and the shaft zaiforlsimulating rollei may 'likewise;:be rotated by, servo. ,.drive., v

It ishould be understood th'at.. ,this'. invention -iS not limitedto'specifi'c details.,ofsconstructioniandi; arrangement 'there'of'jherein' ,-illustrated, and 'that changes and modifications lm'ay, occur; tdone skilled in" the-art without ffd'epa'rting from thee spirit "of the invention.

I claim? 1. Aircraft training W apparatus. comprising; a

: diapositive generalliy sphiericialjfin, shape. res

senting'agpanorama, meansfor moving saiddiaa positive'in azimuth'in response to "steering conetrol, means for moving said .diapositive in a di-' rection to simulate-pitch"in"response to altitude v-i control;' a source"'of' ill'umination" at 'fone side fol" said diapositive;'- projection apparatus" at? the: other side thereof opposite 'saidsourceymeans for operating said 'proj ec'tio'n apparatus to simulate rollg and ascreen upon-which amortion of said panoramais projectedfi 2. Aircraft trairiirig apparatus comprisingea ele'ment" havingia sphericalsurface presentingv terrestial scene.,- meansifon moving said elemen irita: directibna'representing pitch; means "for: may

- ing said elementdn asdirection representing: turn-,

ai'sounce iotillumination adjacent to said elementaproiect-i'onarapparatusassociated therewith, means; for operatingasaidcr projection i apparatus-: indees pendently tofa 'said iiterresti al-lscene-:elemen't to 'rep resent roll; andrazscreen'zupomwhicniza portion mfg said. sceneriseprojectedm 3: "Aircraf-t training; apparatusfor studentspilotsi:comprising adiapositivepresenting a. subs-w stantially continuous .panorammimcansifor move a ingssaididiapositiveainl azimuthiandein; pitch a1;

rection in accordance with simulated maneuvers by the pilot, a source of illumination located at one side of said diapositive, projection means at the other side thereof opposite said source, means for rotating said projection means about the projection axis thereof to represent roll, a grounded cockpit for the student, and a screen forming a part of said cockpit upon which a portion of said panorama is projected 4. Aircraft training apparatus for student pilots comprising a diapositive generally spherical in shape presenting a panorama, means for rotating said diapositive about a generally horizontal axis to represent pitch, means for rotating said diapositive about a generally vertical axis to represent turn, a source of illumination at the inner side of said diapositive, projection prism structure at the outer side of said diapositive opposite said source, means for rotating said prism structure about the projection axis thereof to represent roll, a grounded cockpit for the student and a translucent screen upon which a portion of said panorama is projected substantially forming the windshield of said cockpit.

RICHARD C. DEHMEL.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS 

